2010-01-06 Katsumi Yamaoka <yamaoka@jpl.org>

	* gnus-util.el (gnus-invisible-p, gnus-next-char-property-change)
	(gnus-previous-char-property-change): New functions.

	* gnus-sum.el (gnus-forward-line-ignore-invisible): Use them.

2010-01-05  Andreas Schwab  <schwab@linux-m68k.org>

	* gnus-sum.el (gnus-forward-line-ignore-invisible): New function.
	(gnus-summary-recenter): Use it instead of forward-line.  (Bug#5257)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index e84ee71..5fdcd90 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,15 @@
+2010-01-06  Katsumi Yamaoka  <yamaoka@jpl.org>
+
+       * gnus-util.el (gnus-invisible-p, gnus-next-char-property-change)
+       (gnus-previous-char-property-change): New functions.
+
+       * gnus-sum.el (gnus-forward-line-ignore-invisible): Use them.
+
+2010-01-05  Andreas Schwab  <schwab@linux-m68k.org>
+
+       * gnus-sum.el (gnus-forward-line-ignore-invisible): New function.
+       (gnus-summary-recenter): Use it instead of forward-line.  (Bug#5257)
+
 2010-01-02  Chong Yidong  <cyd@stupidchicken.com>
 
        * message.el (message-exchange-point-and-mark): Rework last change to

diff --git a/lisp/gnus-sum.el b/lisp/gnus-sum.el
index 658193b..86244a9 100644 (file)
--- a/lisp/gnus-sum.el
+++ b/lisp/gnus-sum.el
@@ -6727,6 +6727,26 @@ Also do horizontal recentering."
 
 (put 'gnus-recenter 'isearch-scroll t)
 
+(defun gnus-forward-line-ignore-invisible (n)
+  "Move N lines forward (backward if N is negative).
+Like forward-line, but skip over (and don't count) invisible lines."
+  (let (done)
+    (while (and (> n 0) (not done))
+      ;; If the following character is currently invisible,
+      ;; skip all characters with that same `invisible' property value.
+      (while (gnus-invisible-p (point))
+       (goto-char (gnus-next-char-property-change (point))))
+      (forward-line 1)
+      (if (eobp)
+         (setq done t)
+       (setq n (1- n))))
+    (while (and (< n 0) (not done))
+      (forward-line -1)
+      (if (bobp) (setq done t)
+       (setq n (1+ n))
+       (while (and (not (bobp)) (gnus-invisible-p (1- (point))))
+         (goto-char (gnus-previous-char-property-change (point))))))))
+
 (defun gnus-summary-recenter ()
   "Center point in the summary window.
 If `gnus-auto-center-summary' is nil, or the article buffer isn't
@@ -6742,16 +6762,19 @@ displayed, no centering will be performed."
                             gnus-auto-center-summary
                            (/ (1- (window-height)) 2)))))
           (height (1- (window-height)))
-          (bottom (save-excursion (goto-char (point-max))
-                                  (forward-line (- height))
-                                  (point)))
+          (bottom (save-excursion
+                    (goto-char (point-max))
+                    (gnus-forward-line-ignore-invisible (- height))
+                    (point)))
           (window (get-buffer-window (current-buffer))))
       (when (get-buffer-window gnus-article-buffer)
        ;; Only do recentering when the article buffer is displayed,
        ;; Set the window start to either `bottom', which is the biggest
        ;; possible valid number, or the second line from the top,
        ;; whichever is the least.
-       (let ((top-pos (save-excursion (forward-line (- top)) (point))))
+       (let ((top-pos (save-excursion
+                        (gnus-forward-line-ignore-invisible (- top))
+                        (point))))
          (if (> bottom top-pos)
              ;; Keep the second line from the top visible
              (set-window-start window top-pos)
@@ -6760,12 +6783,12 @@ displayed, no centering will be performed."
            ;; visible, or revert to using TOP-POS.
            (save-excursion
              (goto-char (point-max))
-             (forward-line -1)
+             (gnus-forward-line-ignore-invisible -1)
              (let ((last-line-start (point)))
                (goto-char bottom)
                (set-window-start window (point) t)
                (when (not (pos-visible-in-window-p last-line-start window))
-                 (forward-line 1)
+                 (gnus-forward-line-ignore-invisible 1)
                  (set-window-start window (min (point) top-pos) t)))))))
       ;; Do horizontal recentering while we're at it.
       (when (and (get-buffer-window (current-buffer) t)

diff --git a/lisp/gnus-util.el b/lisp/gnus-util.el
index 28a8c5d..f5679ee 100644 (file)
--- a/lisp/gnus-util.el
+++ b/lisp/gnus-util.el
@@ -969,6 +969,29 @@ If there's no subdirectory, delete DIRECTORY as well."
                          (overlay-get overlay 'face))
                        (overlays-at pos)))))))
 
+(if (fboundp 'invisible-p)
+    (defalias 'gnus-invisible-p 'invisible-p)
+  ;; for Emacs < 22.2, and XEmacs.
+  (defun gnus-invisible-p (pos)
+    "Return non-nil if the character after POS is currently invisible."
+    (let ((prop (get-char-property pos 'invisible)))
+      (if (eq buffer-invisibility-spec t)
+         prop
+       (or (memq prop buffer-invisibility-spec)
+           (assq prop buffer-invisibility-spec))))))
+
+;; Note: the optional 2nd argument has a different meaning between
+;; Emacs and XEmacs.
+;; (next-char-property-change POSITION &optional LIMIT)
+;; (next-extent-change        POS      &optional OBJECT)
+(defalias 'gnus-next-char-property-change
+  (if (fboundp 'next-extent-change)
+      'next-extent-change 'next-char-property-change))
+
+(defalias 'gnus-previous-char-property-change
+  (if (fboundp 'previous-extent-change)
+      'previous-extent-change 'previous-char-property-change))
+
 ;;; Protected and atomic operations.  dmoore@ucsd.edu 21.11.1996
 ;; The primary idea here is to try to protect internal datastructures
 ;; from becoming corrupted when the user hits C-g, or if a hook or